I think there's a main principle in the Universe that could be stated as:

"The purpose of the existence is to enjoy life and if we can't we can think and work to make it possible."

The situation now is that we cannot really totally enjoy life because there's lot of problems (diseases, aging, violence, questionable foods and drinks, the fact that we must work a lot to have a "house" to live, clothing,etc, etc...)

Does this answer your question?

Religions says some "God(s)" created the Universe perfectly and humans "putrified" it or that our "souls" are here to pay some pain for something we could have made in other lifes, in summary that we (humans) are guilty.
Science has a compatible approach: That Nature is perfect and humans only bring pollution (all kinds: chemical, structural, visual, auditive, etc, etc).

I think you are confusing things.
One thing is the purpose of our own lifes but the the opening post of this thread refers to which would be the purpose of the existence of the Universe and everything in it.
Of course our own purposes in our lifes will be those we would "invent" only but I think a more general purpose for the entire Universe and all possible living beings could be expressed as I have done:

"The purpose of the existence is to enjoy life and if we can't we can think and work to make it possible."

Of course is not a "revelation" of any kind.
Is just what I think at the end everybody do in the World.